Brown marmorated stink bugs cluster on warm walls each fall and overwinter in attics and wall voids. Timing the treatment is everything.
An invasive that loves the mid-Atlantic
The brown marmorated stink bug arrived in the mid-Atlantic in the late 1990s and Delaware sits squarely in its worst range. It feeds on crops and ornamentals all summer, then seeks shelter as days shorten.
Why the sunny wall
They gather on south and west-facing walls because those surfaces stay warm into the evening. From there they work into attic vents, soffit gaps, window frames and siding seams, then spend the winter dormant in voids - reappearing indoors on warm winter days.
What actually works
Exclusion first: screen attic and gable vents, seal window and door frames, repair damaged soffits. An exterior treatment applied before they cluster - late September in Delaware - is far more effective than anything done after they're inside.
Don't vacuum them with a regular vacuum unless you want the smell in the machine for a month.
Need help with this in Delaware?
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(302) 602-9239More Delaware pest guides
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